Advanced low-loss and compact LTCC transmission lines and passive components for microwave and millimeter-wave applications

Abstract

The trend to include as many services as possible in small low power devices, along with the necessity of supporting the broad available spectrum at millimeter-wave frequencies bring to attention the importance of the minimization and integration techniques, particularly at high frequencies. The level of integration that is needed to include many bands at microwave and millimeter-wave frequencies poses stringent challenges in terms of high performance, low power consumption, transparent transitions and interconnections, and the number of required embedded passive components. Low temperature co-fired ceramic multilayer technology with its flexible and mature fabrication process provides unique and superior solutions to design highly integrated circuits and address the aforementioned challenges. In light of the above discussion, our objective in this thesis is to address some of the above challenges by improving the performance of the state of the art designs and also by introducing new structures. To reach to this end we also modified and advanced the fabrication techniques to make it possible to realize ultra low-loss structures both at microwave and millimeter-wave frequencies. At microwave frequencies, we proposed a new set of LTCC integrated lumped elements. In our designs, we have used inner air-cavities and a novel structure to make the conductors suspended. These suspended components show significantly better performance in terms of both Q and SRF compared to the previously reported works. Furthermore, with the aid of these enhanced performance components, we have fabricated and successfully measured an LTCC lumped element filter at Ku-band for the first time. At millimeter-frequencies, we have focused on LTCC integrated waveguides. An empty LTCC integrated waveguide has been fabricated to realize ultra low-loss integrated waveguide at 60 GHz. Also, a novel transition from this transmission line to coplanar waveguides has been proposed. This transition is significantly shorter than other reported transitions while it shows better performance. In addition, a novel guiding structure called vertical LTCC integrated waveguide has been proposed which allows us to design out-of-plane structures and also transfer signal in the perpendicular direction to the surface. A complete set of waveguide building blocks have been realized for this new transmission line. Furthermore, an E-plane power divider, a coupler, and a filter have been fabricated and successfully measured at V-band.

Date	19 Dec 2018
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Ammar B. Kouki (Supervisor)